Positive relay



Feb. 5, 1946'. F. D. JOESTING 2,394,38fi I POSITIVE RELAY Filed July 2,1945 2 Sheets-Sheet 1 IN V EN TOR.

Patented Feb. 5, 1946 UNITED STATES PATENT OFFICE v 2394,18 roams RELAYFrederick D. Joe sting; Oak Park, ill assignor to Minneapolis-HoneywellRegulator Company, Minneapolis, Minn, a corporation of 1 DelawareApplication July 2, 194e, Serial No. 493,243

9"Clai nis.

. This invention relates in general. to, a pneumatically operatedrelayand in particular to one of theVpositivev type which eifects a positivepositioning of a valve mechanism in one of two positions or the other inresponse to increase orv de crease of pressure to the relay to .apredetermined point, the valve mechanism being, thereby operable at onlysaid predetermined point, regardless of the rate of supply or dischargeof compressed air to the relay. l 1 A q Qneobject is to provide acomparatively simple snap .acting. mechanism for transferring the motionof a lever moving in response to pressure changes to an actuated elementwhich controls the valve mechanisrrn I i A. further objectis to-providea positive relay wherein avalve or the like controlled by the relay isoperated to wide open or fully closed position in response to the relay,the relay being so designed that a three-wayvalve mechanism thereof maybeconnectedfor direct'or reverse action of a valve controlled thereby oras a diverting relay operating a pairof valves selectively. v 7

Another object is to provide pressure; responsi ve ineans for actuatingthe relay, which means includes an adjustable range spring, the pressureresponsive means being connected with an actuating lever in a novelmanner and the pressure responsive means and. range spring beingmounted. in alignment, so as to minimize the forces im-. posed on theactuatinglever, whereby the lever may be of comparatively lightconstruction; A relatively light toggle spring can be used to effectsnap action between the lever and the valve mechanism, theconstruction-lending itself particularly to ease of manufacture andassembly, and to thepossibilityof the control point being adjusted oversubstantially the entire range of pressures used in pneumatic controlinstallations ofthis general type. I U .,.Sti11 .a further object is toprovide awelllbalanced arrangement of parts in the snap acting mechanismwhereby the actuatinglever is pivoted to the frame of, the controlstructure at two widely separated points andthe'operative connecti olnbetweenthe pressure responsive means and the lever also includes a pairof pivots spaced aisubstantial distance fromeach other, the togglespring connection between the lever, and the valve mechanism being alsarranged :for good balance and an absence vof laterallpressureonthe-pivots With these and other objects in view, my invention consistsin the construction, arrange merit and combination of the various partsf my device, whereby the objects contemplatedare attained, ashereinafter more fully set forth, pointed out in my claims andillustrated in the accompanyingdrawings; in. which: k

Figure 1 is an e larged top. plan view of a positive relay-embodying myinvention;

Figure 2 is a vertical, sectional 'ew thereof as taken on the line 2--2of Figure l, and showing the parts in low pressure position;

Figure 3 is a similar, sectional View showing the parts inhigh pressureposition; v v

Figure 4 is a horizontaLsectional view on the line 4-4-of Figure. v3,showing the porting arrangement of the valves of the relay;

Figure 5 is .a vertical, sectional view on the line 5-5 of Figure 3'; Ie V r i Figures 6; '7 and, 8 are diagrammatic views showing my relayconnected in a pneumatic systern for use, respectively, as adirectrelay, a reverse relay, and a diverting relay; 7 .Figure 9 is asectional view on the line 9 -3 of Figure 3, showing a pair of pivotsduringone step ofstheir installation, and v Figure, 10 is. a. similarview showing the pivots in their final installed position. e n V On theaccompanying drawings, 1 have used the reference numeral Ill to indicatea base on which. the. mechanism of myDOS tive relay is mounted, On thebase 19,1 mount a valve wil i2, by means of screws l lextending throughbi furcated feet loofth e valve body and threaded into the basal Thevalve body lZin turn serves as a mount for a pair of end castings l8 and20 secured thereto as by screws 22 and 24, respectively. 3

. Thevalve body l2 andthe two castings l8 and 20, together with threecover plates 26, 28 and that would result in sluggishness of operationor loss of.,sen's'itivity. I

. .A further object is to providecertain pivot connections which arevinstalled in anovel manner so that a sleeve actuated by the pressureresponsive, means may fit in an opening of the actuating leverwith the.pivots initially received far enough in the sleeve topermit them topass intezthe opening and thereafter spread apart to substantially fillthe opening.

30 secured in position by. screws ,32 having knurled heads, constitute ahousing for the relay mechanism a l Thecasting. 2!! has therein adiaphragm chamber-34 spanned by a pressure responsive, diaphragm 36.,The diaphragm 3B is retained in po sition by a diaphragm casingSSecured as by screws 40 to the casting 2B. Theedge ofthe diaphragmconstitutes a gasket between the end casting Zll and thediaphragm casing38 Within the casing 38, a diaphragm chamber ls is provided and it is incommunication with a boss l, which in turn constitute an inlet for thediaphrag'm chamber I as from apipeline t2. 7

Against opposite sides of the center of the diaphragm, I provide discs44 and 4% secured ,t0

gether as by rive-ting e, tud 18 which extendsfrom the disc 44 andthrough the diaphragm and the disc 46. The disc 44 also has a socketmember 50 receiving one end oiastud 52. Theother end of the 513115.52 isthreaded into one end of a sleeve 54. Against a flange 56 adjacent theop posite end of the sleeve 54, I seat an adjusting spring 58. Theadjusting spring is interposed b tween the flange 56 and a second flange69 formed on a sleeve 62. The sleeve 62 is threaded on an adjustingscrew 64, the screw having a bearing portion 69 rotatable in an opening68 of the end casting I8. The spring 58 urges the adjusting screw 64 tomove toward the left and it is limited in such movement by a flange 70formed on the screw and engaging a shoulder I2 of the casting I8.

From the construction of the parts just described, it will be obviousthat the spring 58 (which is always under compression) keeps the flangeI against the shoulder I2 and the right hand end of the stud 52 in thesocket 50 in opposition to any air pressure introduced from the pipe 42into the diaphragm chamber I Overtravel of the diaphragm may be limitedby an adjusting sleeve I4 screw-threaded into'the casting 20 andsurrounding the socket member 50, as shown in Figure 3. In the oppositedirection, as shown in Figure 2, the disc 46 may seat against a boss I6in the diaphragm casing 38, when the air pressure is relieved. The bossI6 is provided with radial grooves 01' is otherwise interrupted toprevent seal-off of the air pressure from the line 42 to the chamber I.

For purposes of determining the adjustment of the spring 58, I providean upwardly extending pointer I8 on the sleeve 62 passing through a slot90 in the cover plate 28. Suitable indicia may be provided on the coverplate, adjacent the slot, if desired, for determining the adjustment atany time. A change in adjustment is secured, of course, by rotating theadjustment screw 64 as by a screwdriver inserted into a slot 82 at theleft-hand end of the screw.

The valve body I2 is provided with three openings 2, 3 and 4 (see Figure4) into which air pipes or copper tube fittings may be screwed. Adjacentthe openings 2 and 4 are valves, indicated generally at V and V Thesevalves, as shown in Figure 3, comprise stems which are slidably mountedin plugs 84 and 86 and heads which may seat against valve seats 88 and90. The open ing 3 in the valve body is common to both valves V and V bymeans of a passageway 3 from the opening 3 into a chamber 3 The chamber3 communicates with both of the valve seats 88 and 90.

The chamber 3 has all but its top formed in the valve body I2, and aseal-off diaphragm 92 serves as the top of the chamber. The seal-offdiaphragm 92 is confined between the valve body I2 and a cover plate 94,screws 95 passing upwardly through the valve body and being threadedinto the cover plate for this purpose. The seal-01f diaphragm 92 therebyforms a gasket around the chamber 3 to prevent leakage.

The valves V and V open into chambers 2 and 4 which communicate,respectively, through passageways 2 and 4 with the openings 2 and 4.

On the cover plate 94, I pivot an actuated lever 96 in the form of arelatively thick plate having a pair of downwardly extending ears 98(see Figure 5). These ears are pivoted to the cover plate 94 by means ofpivot screws I00. tightly threaded into the ears and having pinlikeextensions I02 into an opening I04 drilled through the cover plate.

The actuated lever 96 carries a pair of screws.

I06 and I08 for opening the respective valves V and V As shown in Figure2, the screw I08 is depressed for opening the valve V (the valve beingspring loaded for normal closing) by contact of the lower end of thescrew with a portion of the seal-01f diaphragm 92 in an openin [I2 ofthe cover plate 94. This portion of the diaphragm is accordinglydepressed and engages the upper end of the valve V to lower it away fromthe seat against the action of the valve spring.

Likewise in Figure 3, another portion of the diaphragm 92 in an openingII4 of the cover plate 94 is engaged by the screw I06 for opening thevalve V the screw I08 at the same time permitting the valve V to closeunder the action of its spring. In accordance with the description justcompleted, it is obvious that the opening 3 in the valve body theopening 2 when the opening 4 is closed oil from the opening 3, theactuated lever 96 being in the position of Figure 3. Communicationoccurs between the openings 3 and 4 and the opening 3 is closed relativeto the opening 2 when the actuated lever is in the position of Figure 2.

For automatically tilting'the lever 96 in response to pressure on thediaphragm 36, I provide a toggle mechanism including an actuating leverH9 and a toggle spring I I8. The actuating lever H6 is in the form of aplate having an opening I20 through which the sleeve 54 loosely extendsand is bifurcated at its lower end to provide a pair of arms I22. Theactuating lever II 6 is pivoted on stationary pivots I24 formed on pivotscrews I26. The screws I26 are tightly screwed into a pair of wings I28formed on the end casting 20, the pivots of the screws extending intoopenings I30 of the lever H6.

The operative connection between the sleeve 54 and the lever H6comprises a pair of pivot pins I32 formed on knurled studs I34, thestuds being received in openings I30-0f the sleeve 54 and the pivot pinsI32 being received in openings I38 of the lever H6.

The mounting of the pivot pins I32 involve a problem due to the sleeve54 being within the opening I20, and the lever II6 being made in onepiece, instead of two pieces, which might be fastened together tosurround the sleeve. In Figure 9, I illustrate how the studs I34 arepushed too far into the openings I36 of the sleeve 54, and a fiat,bladelike tool I40 thrust into the opening of the sleeve 54 and thenrotated to the position of Figure 10 after the pivot pins I32 arealigned with the openings I38. The parts are now in assembled positionfor proper operation, and due to the knurling of the studs I34 theyremain rigidly in the position assumed in Figure 10.

The toggle spring II 8 comprises two pairs of arms I 42 and I44connected together by a pair of coils I45. The coils are under suchtension as to tend to spread the arms I42 relative to the arms I44,thereby acting as a resilient thrust element between pivot points I54and I48. The pivot point I54 is in the form of a notch in a stud I50threaded into an opening I52 of the actuated lever 96, while the pivotpoint I48 is in the form of a pair of out-turned ends on the extremitiesof the tog le spring arms I44 and received in openings I49 of the arms I22 of the actuating lever IIS. This is perhaps best shown in Figure 5,wherein it will benoted that the two arms I42 have a cross piece I 56between them for engaging. in the notch [46. The purpose of threadingthe stud I50 in the lever 96 is so that it can be vertically adjustedfor a purpose which I2 is in communication with will hereinafter appear.The I stud is slotted as illustrated in the drawings for the purpose 'ofproviding sufficient friction to hold the =stud at any adjustedposition. The stud, of course, is spread enough by opening the slot to'give the desired amount of holding friction.

The degree of tipping of the actuatedleversfi may be controlled byadjusting screws I58 and I60, the lower ends of the screws-striking' thecover plate 84 when the valves V and V areopen as shown in Figures 2 and3 respectively. The screws I06 and I08 are adjustable to give properclearance'for the upper ends-of the valves V and V with relation to theunder'surface-of the-sealoii diaphragm e2 when the valves are in c'losedposition, as evident'in Figures 2,and'3.

To look the screws I95, I58, I58 and I60 against loss of adjustment, twospring wires I62 are provided and lie against thescrews and the stud I50 in the manner shown in Figure 1. These wires are under bendingtension so as to irictionally engage the screws and thus hold themnormally adjusted except when a screwdriver is applied thereto.

The purpose for making the stud E2 adjustable in the sleeve 5 is toinsure that the actuating lever I will swing thesame distance to theright as to the left for making the snap action of the spring 'IIB equalin both directions. Thecadjusting sleeve HI is first adjusted to givethe desired travel of the stud 52 and then the stud is adjusted relativeto the sleeve 54 until the throw of the lever H6 is 'equal on both sidesof a center line from the pivot center of the actuated lever-96 to thestationary pivots I24. The stud Ibtmay be adjusted upwardly ordownwardly depending on whether a stronger or weaker snap is desirable,as adjustment upwardly increases the spreading tendency of the spring H8and adjusting it downwardly decreases its strength.

In Figure 6, I show how my positive relay may be connected with a mainIfi i supplying compressed air to the relay and to a device forcontrolling the relay, such as a pneumatic thermostat IE5. The main, itwill be noted, is connected to the opening 2, and a pressure operatedvalve 163, such as the type having a bellows operator, is connected tothe opening 3 which serves as an outlet. The relay in this case isdirect-acting.

When the thermostat I56 increases the pressure supplied from the mainI54 to the diaphragm 36 until it reaches the control point determined bythe setting of the adjusting spring 58, the lever IIS will be moved fromthe solid line position of Figure 2 to another position, such as the oneshown by dotted lines. This brings the toggle spring I I8 from its fullline position to its dotted line position, in which latter position thepins I24, I32, I48 and I54 have almost reached a position of alignmentor dead center. The toggle spring I I8 in attempting to open up orspread its arms Hi2 and IM will thereupon snap the actuated lever 96from the position of Figure 2 to the position of Figure 3, as soon asthe pressure of the spring under the valve V is enough to. move theactuated lever 96 to the dead center position. Thus the spring under thevalve V assists in the final movement of the actuated lever past thedead center position, and similarly whenthe parts are operated in theopposite direction, the spring under the valve V assists in moving theactuated lever past the dead center position. The strength of the valvesprings therefore enters into this operation and affects to some extentthe difier= ential of the relay. There isalso a slight modification ofthe action due to air pressure under the seal-oh diaphragm-92, but sincetheair'on the portion over the valve V -is atthe same value asthe airpressure overthe valve V they are substantially equalized and themodifying effect is very slight.

The adjusting or mainspring 58'and the diaphragm 36 due to theirrelation in alignment with each other minimize the pivot load, thusmaking the relay very sensitive.

The actuating lever I'IIi moves the actuated 1ever96, the two leversbeing independent of each other, except through the snapspringconnection I I8, and thus the lever 96 operates freely withouthaving to drive back through thelever II6 and beopposed by the mainspring or the diaphragm.

It will'also be noted that the two pivots I124 are spaced a substantial.distance from, each other and so are the two pivots I32 and the twopivots I48; whereas the pivot Hi l is located in a plane substantiallybalanced between the two pivots I48. This results in the lever I I'iibeing held against any cooking action relative to its pivots and theforces are so equalized or balanced as to minimize any-lateral bias ofthe toggle spring on theactuating lever H t. The differential ofoperation of the relay is thereby minimized due to elimination offriction caused by binding action and remains constant throughoutsuccessive operations of the relay without variation from the originaldifierentia-l spread. I am thus insured that the relay will operatesimilarly throughout its entire life. 7

The in-line arrangement of the adjusting spring 58 and the diaphragm 35also makes it possible to have a wide degree of adjustment, for instance, between 4 and 1'7 pounds 'per square inch where the relay isdesigned for a maximum of 17 pounds. I

Referring again to Figure 6, air flowwill be to valve IE8 through thevalve V as indicated by the solid line arow when the rela is in theposition of Figure 3 (with valve V open and valve Vi closed). The valve[58 (normally open) will therefore be closed.

Whenthe pressure is reduced in the opening I by the thermostat, thecontrol point lowered by the amount of differential will finally bereached, whereupon therela' will assume the position of Figure 2,permitting air flow from the diaphragm of the valve :68 to atmospherethrough the opening 4 as indicated by the dotted arrow, and therebyopening the valve I68.

The relay may be hooked up for reverse action, as shown in Figure 7,wherein the valve 'IIBS (again normally open) has the air dischargedfrom it as indicated by the solid line arrow when the thermostat I66increases the pressure of the air from the main I54 to the opening I ofthe relay.

Valve V is open at that time for permitting air to bleed from thebellows of the valve I68 to open it. When the thermostat IE6 is inposition for reducing, the air pressure from the. openmg I of the relay,the valve V is opento permit air no themam I64 to enter the bellows ofthe valve 868, as indicated by the dotted arrowar ld thereby close thevalve I68. p

when my relay is to be used for diverting air with respect to twodifferent branches, such as the branches I'Iii and I12 in Figure 8, themain IE4 is connected with the opening 3 and the thermostat I66, whenpermitting increase of air pressure to the opening I, results in air asthe main passing through the vaivew to the op n: ing 2 and the branchIII), as shown by the solid line arrow. When the thermostat I56decreases the air pressure from the opening I, the valve V opens fordiverting air from the main 164 to the branch H2 instead of the branchH6, as indicated by the dotted arrow.

Some changes may be made in the construction and arrangement of theparts of my device without departing from the real spirit and purpose ofmy invention, and it is my intention to cover by my claims any modifiedforms of structure or use of mechanical equivalents, which may bereasonably included within their scope without sacrificing any of theadvantages thereof.

I claim as my invention:

1. In a device of the character disclosed, the combination of anactuated element for positioning in either one of two positions, anactuating element, an adjusting spring in alignment therewith foropposing the movement of said actuating element, a pivoted lever, saidactuating element having one portion pivoted thereto and another portionconnected with a diaphragm, said lever and said diaphragm constitutingthe supporting means for said actuating element and moved in responsethereto, said spring being adjustable to change the control point ofsaid pivoted lever, and a toggle spring connecting said lever with saidactuating element, said toggle spring having a pair of arms pivotedrespectively to said lever and said actuated element, and a coilconnecting said arms together and constraining them to move away fromeach other.

2. In a control structure, the combination of an actuated element forpositioning in either one of two positions, an actuating elementtherefor, a lever operatively connected with said actuating element andmoved in response thereto, and a toggle spring connection between saidlever and said actuated element, and having a pair of arms pivoted tosaid lever and a second pair of arms pivoted to said actuated element,and having a coil connecting each pair of said arms to the other pairthereof and constraining them to diverge in relation to each other.

3. In a device of the actuated element movable between two positions, anactuating element, a range spring opposing movement of said actuatingelement, and a toggle spring connecting said actuating element with saidactuated element, said toggle spring having two pairs of arms with onepair pivoted to one of said elements and the other pair pivoted to theother of said elements, and a coil connecting one of said arms of eachpair together and constraining their outer ends to move away from eachother.

4. In a device of the character disclosed, a frame, an actuating elementand an adjusting spring supported by said frame in alignment with eachother, an actuating sleeve between said actuating element and saidadjusting spring, an actuating lever having an opening surrounding saidsleeve and pivoted relative to said frame, said actuating lever havingpivot openings, pivots projecting from said actuating sleeve and intosaid pivot openings, said pivots being slidable in- .wardly relative tosaid sleeve to permit the sleeve to enter said actuating lever openingand the pivots to move outwardly to engage in the pivot openings of saidactuating lever, an actuated element for operation by said actuatinglever, and an operative connection between said actuating lever and saidactuated element.

character disclosed, an

5. In a control structure, the combination of a frame, an actuatingelement and an adjusting spring supported by said frame, an actuatingsleeve between said actuating element and said spring, an actuatinglever having an opening surrounding said sleeve and pivoted relative tosaid frame, pivots projecting from said actuating sleeve and pivotallycoacting with said actuating lever, said pivots being slidable inwardlyto permit said sleeve and the pivots to enter said actuating leveropening and the pivots to then move outwardly to pivotally engage saidactuating lever, said pivots being retained frictionally in theiroutward positions, control mechanism for opera tion by said actuatinglever, said control mechanism having an actuated element, and anoperative connection between said actuating lever and said actuatedelement.

6. In a control device, a frame, actuating means and an actuating sleevemounted in said frame, said actuating sleeve being responsive to saidactuating means, an actuating lever having an opening surrounding saidsleeve and pivoted relative to said frame, said actuating lever havingpivot openings, pivots projecting from said actuating sleeve andpivotally coacting with said pivot openings of said actuating lever, anactuated element, and an operative connection between said actuatinglever and said actuated element comprising a toggle spring.

7. In a control device, actuating means including an actuating sleeve,an actuating lever pivotally mounted and having an opening surroundingsaid sleeve, said actuating lever having pivot openings, pivotsprojecting from said actuating sleeve and into said pivot openings ofsaid actuating lever, said pivots being slidable inwardly relative tosaid sleeve to permit it to enter said actuating lever opening and saidpivots to move outwardly to engage in said pivot openings, an actuatedelement for operation by said actuating lever, an operative connectionbetween said actuating lever and said actuated element comprising atoggle spring having a central U-shaped arm terminating in coils, saidcoils having terminal ends constituting a double arm, and means forpivoting one of said arms to said actuating lever and the other of saidarms to said actuated element, said coils tending to spread said arms.

8. In a device of the character described, an actuating element, anactuated element for operation by said actuating element, an operativeconnection between said actuating element and said actuated elementcomprising a toggle spring having a central U-shaped arm terminatin incoils, said coils having terminal ends constituting a double arm, andmeans for pivoting one of said arms to said actuating element and theother of said arms to said actuated element.

9. In a device of the character disclosed, the combination of anactuated element for positioning in either one of two positions, anactuating element, an adjusting spring in alignment therewith foropposing the movement of said actuating element in response to a rise inpressure thereagainst, a pivoted lever, said actuating element beingpivoted thereto and supported thereby in conjunction with a connectionof said actuating element with 9, diaphragm at a point spaced from saidpivotal connection and moved in response thereto, said spring beingadjustable to change the control point of said pivoted lever, and a snapacting connection between said lever and said actuated element.

FREDERICK D. JOESTING.

